16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Grille Compatible With Duct 8in 75"H – fits a 8"

75"H – fits a 8" X 4" duct opening

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 24" OR 24" x 20" duct opening (measured at the opening)

ensuring a perfect fit

75"H – fits a 14" X 4" duct opening

16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Grille Compatible With Duct 8in 75"H – fits a 8"+ Product Details Size 16" x 18" or 18" x 16" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 17. 75" X 19. 75". High Quality High quality, rust free aluminum construction with smooth finished edges and counter sunk screw holes (screws included); no sharp edges.. Installation Location sidewall and ceiling. Design Cubic core eggcrate design Offers highest airflow efficiency at almost 95%, reducing